1. Field of the Invention
This invention relates to an air cell for an internal combustion engine in which air contained in the main volume of the combustion chamber is augmented by additional air compressed into an auxiliary volume by the piston. During the engine's expansion stroke, the pressure in the main volume of the combustion chamber decreases, and the air within the air cell is discharged through a plurality of jets and allowed to bore into the combustion products within the main combustion chamber, thereby providing additional air, and sometimes fuel, for combustion. The discharge of air provides additional turbulence and enhances swirl, which promotes complete combustion.
2. Disclosure Information
The Society of Automotive Engineers Technical Publication 831297 discloses an air cell direct injection diesel engine, in which the air cell comprises a relatively massive affair taking a good deal of the space within the cylinder head. The cell is housed entirely within the cylinder head and has only a single nozzle for admitting the contents of the cell into the main combustion chamber.
U.S. Pat. No. 4,483,289 to Paul et al. discloses a prechamber diesel engine which, too, has a relatively massive chamber housed within the cylinder head, with but a single nozzle for discharging the contents of the prechamber into the main combustion chamber.
It is an object of the present invention to provide an air cell for an internal combustion engine which is compact and relatively easily manufactured, but which produces superior results by providing a plurality of passages for admitting the contents of the cell into the combustion chamber.
U.S. Pat. No. 1,703,653 to Barrett discloses an air cell having a uniflow design in which air is extracted from the cylinder through a first set of passages disposed about the outer periphery of the combustion chamber and subsequently conducted through such discrete passages to an annular supply chamber disposed about a centrally mounted fuel injector. A second plurality of passages extending from the annular space causes air to impinge upon the fuel spray emanating from the injector. Unfortunately, because of the lengths of the passages and the presence of such flow obstructing devices as check valves, the device shown in the '653 patent would be expected to perform poorly, while being expensive and difficult to construct, because of the need for numerous supply passages and associated valves wholly within the cylinder head. Also, because air is discharged about the centerline of the cylinder, mixing of the air with the contents of the combustion chamber will not be nearly as complete as with the design of the present invention, in which the air is discharged about the outer periphery of the combustion chamber.
U.S. Pat. No. 2,305,208 to Trammell, Sr., et al. discloses a cylinder having an inset defining a passage into the combustion chamber from which a jet of high velocity burning material bores into the combustion chamber after passing over a specially modified spark plug. The device of the '208 patent is asymmetrical, and its association with a spark plug prevents its use with a plurality of jets entering the combustion chamber. As with other single entry designs, the efficiency of operation would be hampered by the inability to obtain good mixing of the entire supplementary air charge.
Automotive designers have used various piston and combustion chamber designs for producing swirl within the combustion chamber U.S. Pat. No. 3,658,046 to Winkler and U.S. Pat. No. 4,162,661 to Nakanishi et al. disclose but two such examples, neither of which provide an air cell action in which air is supplied to a primary combustion chamber after a piston has begun its downward stroke.
Engine designers have used port liners with inlet ports having different configurations as yet another means to increase swirl within the cylinder. U.S. 1,172,472 to McCornak, U.S. Pat. No. 1,664,782 to Magdeburger, U.S. Pat. No. 2,231,392 to McCarthy, and U.S. Pat. No. 2,244,749 to Ware disclose inlet ports in cylinders so as to cause swirl. None of these arrangements, however, can provide additional air once the piston has moved upwardly in the cylinder a sufficient height to cut off the inlet ports.
It is an object of the present invention to provide an air cell which is both compact and easily manufactured.
It is yet another object of the present invention to provide an air cell system which has multiple air jets for the purpose of enhancing the delivery of the air contained within the cell to the primary combustion chamber in multiple locations, whereby a more even delivery of air is achieved than with prior air cells.
It is an advantage of the present invention that the present system obviates the need for a conventional cylinder head gasket.
Other objects, features and advantages of the present invention will become apparent to the reader of this specification.